Memory is one type of integrated circuitry, and is used in electronic systems for storing data. Integrated memory is usually fabricated in one or more arrays of individual memory cells. The memory cells are configured to retain or store memory in at least two different selectable states. In a binary system, the states are considered as either a “0” or a “1”. In other systems, at least some individual memory cells may be configured to store more than two levels or states of information.
One type of memory is phase change memory (PCM). Such memory utilizes phase change material as a programmable material. Example phase change materials that may be utilized in PCM are chalcogenide materials.
The phase change material reversibly transforms from one phase to another through application of appropriate stimulus. Each phase may be utilized as a memory state, and thus an individual PCM cell may have two selectable memory states that correspond to two inducible phases of the phase change material.
The electrical stimulus utilized to transform PCM from one phase to another may have an associated “programming current” which is a minimal current suitable for achieving the desired transformation. It can be desired to develop memory cells having reduced programming current relative to conventional memory cells in order to, for example, extend battery life of portable electronics, reduce overall current requirements of integrated memory circuitry, etc.
PCM may be incorporated into memory arrays. Problems may be encountered with thermal disturbance (i.e., crosstalk) between adjacent PCM cells within a memory array. It is desired to reduce or eliminate such thermal disturbance.
It is desired to develop new PCM architectures which may reduce programming current relative to conventional architectures, and/or which may reduce thermal disturbance relative to conventional architectures. Also, it is desired to develop methods of forming the new PCM architectures.